Disc wheels for pneumatic tires have come into extensive use on large vehicles, e.g. trucks, earth movers, aircraft and the like. Tires for such vehicles are extremely difficult to remove from the wheel and repair or replacement generally require use of power equipment to "break" the tire bead from the wheel. Such equipment known to the prior art is very heavy and usually stationary, thus requiring the tire and wheel be transported to a central location for repair or replacement. Such a requirement is expensive and time consuming and sometimes causes expensive equipment to be idle while a tire is being repaired or replaced. Replacement or repair of a tire on such a wheel can also be very dangerous in that the rim may fly off with great force.
Generally, disc wheels incorporate a separable rim which affords lateral support for one of the tire beads when a tire is mounted on the wheel. Conventionally, such rims take the form of an open ring so that they may be seated in a rim gutter on the wheel, and removed therefrom as to dismount a tire. Although disc wheels have come into widespread use and are certainly effective, the operation of mounting tires on such wheels is sometimes rather dangerous. This danger arises for example, when foreign particles, e.g. dirt or small stones, go unnoticed in the rim gutter and cause the rim to disengage from the wheel when the tire is inflated. Disengagement may also occur in the event of a worn wheel or slight misalignment of the rim and the rim gutter.
Normally, a wheel rim does not disengage until substantial force is applied thereto, such as during the process of inflating the mounted tire. As a consequence, the rim is usually disengaged by a considerable force and accordingly can be very damaging. The risks involved by a forcefully disengaged rim are increased by the fact that the repairman is normally required to be in close proximity to the wheel, so as to hold an air hose coupled to inflate the tire.
In general, various structures have been previously proposed to minimize the danger attendant a disengaged rim with the inflation of a tire that has been freshly mounted on a disc wheel. However, such structures have been somewhat inadequate. Typical devices include a plurality of arms which are affixed to the wheel and act as rim-retaining apparatus during the inflation of the tire. The arms are secured to the wheel on a shaft which extends axially to the wheel with the arms being secured to the wheel by means of a locking nut or clamp. Such devices normally require a relatively large amount of time to secure the arms to the wheel prior to inflation of the tire.
The present invention provides a rapid, safe and convenient safety apparatus which may be readily transported directly to a vehicle for on the site tire repair or replacement and includes rim retaining means for use during inflation of a tire having a separable wheel rim.